Mill the sugar on Speed 9 for 6 secs til you have fine icing sugar.
Add fruit to bowl, along with egg white if using and 500g ice.
Bring speed up to 10, use spatula to move the mixture around for up to 30 secs until the mixture moves by itself.
Taste and check for sweetness levels and consistency to your liking, then add up to 100g more ice through the lid while on Speed 10 for up to another minute or longer. The raspberry seeds need that extra bit of time if you'd like a smoother texture.
Eat immediately or freeze in a container, then churn once more on Speed 8 just before serving. I have tried putting the mixture back in the freezer after the second churn to keep it for a longer period without needing to process it again before eating, and that seems to work pretty well.